SOLUTION: The demand equation for a certain type of printer is given by D = -200p + 35,000 The supply equation is predicted to be

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Question 87254This question is from textbook Beginning Algebra
: The demand equation for a certain type of printer is given by
D = -200p + 35,000
The supply equation is predicted to be
S = -p square + 400p - 20,000
Find the equilibraum price This question is from textbook Beginning Algebra

Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
Not too sure what the equilibrium price is ie how to get it. I am assuming that it is where both equations are the same. If this is true then:

+D+=+-200p+%2B+35000+
+S+=+-p%5E2+%2B+400p+-+20000+

so when these are equal:
+-200p+%2B+35000+=+-p%5E2+%2B+400p+-+20000+
+p%5E2+-+600p+%2B+55000+=+0+

+p+=+%28-b+%2B-+sqrt%28b%5E2+-+4ac%29+%29%2F%282a%29+

+p+=+%28600+%2B-+sqrt%28360000-220000%29+%29%2F%282%29+
+p+=+%28600+%2B-+sqrt%28140000%29+%29%2F%282%29+
+p+=+%28600+%2B-+374.17+%29%2F%282%29+
so +p+=+%28600+%2B+374.17+%29%2F%282%29+ or +p+=+%28600+-+374.17+%29%2F%282%29+
so +p+=+%28974.17%29%2F%282%29+ or +p+=+%28225.83%29%2F%282%29+
p = 487.1 or 112.9

Now this gives 2 valid answers so i am not too sure whether i have given you the correct method. Sorry.


cheers
Jon